The invention relates to a heating element comprising an electrical current conductor and also to a heatable pane comprising such a heating element.
For heat generation in a heating element it is usual for current to be passed through a current conductor. In this arrangement, as a result of a drop in voltage at an ohmic resistor, electrical energy is converted into heat energy. Heating elements of this kind are used for multifarious purposes. For the use of heating elements in the case of heatable panes it is known to insert thin wires into the pane and to use these wires as current conductors for the purpose of heating the pane. In addition to relatively high production costs, this entails obstructions to vision and also nonuniform heating of the pane.
The pane referred to encompasses not only mineral glass panes but also panes made of plastic glasses. The use of panes of this kind with a heating element is of interest in particular for motor vehicles and aircraft. Possible fields of application, additionally, are heatable visors of protective helmets, such as motorcycle helmets or mirrors or displays of measuring instruments which are used, for example, in polar regions.
The use of electrically conductive films as a heating element is also known. Their field of use, however, is limited, owing to a limited current flow through them, and to inadequate transparency. At increased current flow, there is often damage to these conductive films, which impairs their functionality. Moreover, the intrinsically conductive polymers that are used in such films have a low long-term stability.